If the programmer is waiting for the computer to finish something the programmer can get down on the floor and do pushups.
Are pushups too easy? Then pin yourself up on your finger tips and thumbs and do pushups without using your palms.. only your tips of the fingers. Then do regular pushups with full palms after you have worn your thumbs/fingers/forearms out on the first few rounds of fingertip pushups. Fingertip pushups might help your arms/hands against carpel tunnel. It should clear out the arms and hands with fresh blood at least. Do not do fingertip pushups every day - only every second or fourth day. Your thumbs may get injured otherwise.
If the push ups are too easy, get a pack sack and fill it with weights. Put the packsack on your back and do pushups as fast as you possibly can. Adding speed and weight to the pushups increases muscle mass.
Pushups are convenient because they allow you to get back to programming immediately. You don't have to go to some exercise machine or club. Pushups also don't require bulky equipment/weight machines. All you need are dumbell weights which are fairly small and cheap, even the 40 pound ones. If you put enough dumbells or other weights in a packsack, you can have a really good workout break.
Strength vs Endurance
You should be able to increase the amount of pushups - or the amount of weight. Obviously if you want to get stronger, then focus on using more weight. However, if you want more endurance then do 40-200 pushups without stopping (or more) and continually increase the total amount (each week, month, etc).
A one arm pushup can be done if you train first on the regular pushup with more weights in the pack sack. It is very hard to do a one arm pushup if you have not added weights to your regular pushup. If you have done excellent benchpress work before then you may be able to do a one arm pushup.
To become stronger, increase the rest time between sets. Do about 5-15 pushups with weights in packsack per set (2-5 minutes rest, 5-15 pushups. Your pulse should be very high if you are doing it right. For me it is about 170BPM-185BPM but it depends on your age. There are some nice maximum heart rate calculators out there.
To obtain endurance, decrease the rest time and focus on doing as many pushups as you can with as little rest. However, in order to have endurance with pushups you will first need to build up strength.. because most people can only do about 20-60 pushups without stopping.. and they hit a peak at about 40-60 pushups where they cannot do any more - even after training. More strength is needed if you hit this barrier because regular pushups are a mixture of strength and endurance.